In conventional magnetic head systems, the magnetic head consists of an electromagnetic arrangement for writing, reading or erasing data on a magnetizable storage medium, movable relative thereto, such as a magnetic disk. Typically, for use with a magnetic disk, the magnetic head is attached to a suspension and lies opposite the disk face.
Rotating magnetic disks of the type in which the magnetic head is in contact with the disk surface when the disk is at rest and flies above the disk surface when the disk is rotating at its operating speed are well known in the field. In such types of rotating magnetic disks, the magnetic head, which is supported on a suspension, rides on a cushion or bearing of air above the disk surface when the disk is rotating at its operating speed. The slider is movable radially on the disk to be positioned over a selected one of a group of concentric recording tracks. The slider is carried on a suspension assembly connected ultimately to an actuator.
Such magnetic head sliders commonly use a two piece core with the separate halves bonded together using high temperature glass. A coil is wound around one of the legs of the core to create magnetic flux. A gap is established using sputtering techniques causing the magnetic flux to radiate to the disc surface or to enable the magnetic flux on the surface of the disk to induce a current through the coil. Sliders of this geometric configuration leave a particular foot print, which has become a standard in the industry. The use of such two piece cores has two inherent disadvantages. First, the gap runs the entire length of the core thereby creating a back-gap in addition to the intended front-gap. The back-gap causes additional flux loss which hampers an improvement of magnetic head sensitivity in reading and writing. Second, once made, the core is a closed loop, and installation of the coil must be accomplished by winding wire through the open center of the core. Since this is done by hand with use of a microscope, this process involves a considerable amount of time and cost.
It is recognized that higher magnetic recording density requires correspondingly reduced disc-to-disc spacing or height of the slider. The need to wind magnetic wire through a coil window in the two piece core as above also puts constraints on the final size of the head assembly. As storage capacities increase, the size of the magnetic head has been reduced significantly. Further reduction, however, will be limited by the need to leave a winding area. Present day technology has brought us to a final head height of 0.024 inches, but only through technology changes will it be possible to reduce it further.